1. Field of the Invention
The present invention relates to a Hall-effect sensor, for example, for use in detecting a crank angle for an ignition timing control apparatus for an internal combustion engine.
2. Description of Related Art
Recently, the Hall effect has been used for such various types of sensors as a position sensor, an angle sensor, and a speed sensor. As such a type of sensor using the Hall effect, there is well known a Hall-effect sensor in which a Hall element, a peripheral circuit such as an amplifier, a waveform shaping circuit, a surge protection element, and a magnetic circuit for generating a magnetic flux are integrally provided with each other by a resin. In addition to it, there is also well known a Hall IC in which a Hall element is fitted in a hybrid integrated circuit on a substrate made of ceramics. When such conventional Hall-effect sensors are manufactured, each of the Hall element, parts of the magnetic circuit and the like are positioned by use of jigs first, and then, a thermoplastic resin or a thermosetting resin is poured into a space surrounding each of them, following which being dried or hardened by a heater. As a result, there exist some problems that it is necessary to provide a lot of jigs for positioning such Hall element and parts in the sensor, that the positioning accuracy of those Hall element and parts is not so high that the sensor is not suitable for mass production, and that sensitivity of the sensor is inferior.